首页 | 本学科首页   官方微博 | 高级检索  
     检索      


A continuous record of Holocene eolian activity in West Greenland
Authors:Nico W Willemse  Eduard A Koster  Babette Hoogakker  Frank G M van Tatenhove  
Institution:a Department of Physical Geography, Faculty of Geographical Sciences, Utrecht University, P.O. Box 80.115, NL-3508 TC, Utrecht, Netherlands;b Department of Physical Geography and Soil Science, University of Amsterdam, Nieuwe Prinsengracht 130, NL-1018 VZ, Amsterdam, Netherlands
Abstract:Eolian landforms are widespread alongside proglacial valley-sandurs in West Greenland and comprise low-relief sand sheets, climbing dunes, and upland loess. Sedimentary facies mainly reflect distance to outwash-source zones and the influence of vegetation cover. The sediments show stratification types typical for poorly to moderately vegetated sand-sheets, alternately laminated silt/peat sequences, and unstratified loess. Twenty-five accelerator mass spectrometry 14C dates provide the basis for the chronostratigraphy of the inland eolian deposits. 14C dates from interstratified sand-sheets suggest that the bulk of eolian sands were deposited prior to 3400 cal yr B.P. and after 550 cal yr B.P. This two-phase formation for the inland dunes most likely reflects local changes in proglacial floodplain development and meltwater rerouting associated with a significant recession of the Greenland ice sheet during the mid Holocene climate optimum. Subsequent floodplain regeneration and renewed sand-sheet formation after 550 cal yr B.P. followed when the ice margin readvanced to its present position. In contrast, atmospheric deposition of regionally derived silt in upland peat mires has been continuous since at least 4750 cal yr B.P. Silt influx data demonstrate a strongly episodic history of the intensity of eolian activity over the past five millennia, which tentatively reflects alternating periods of (winter) aridity associated with the variable incursion of maritime air masses over the interior ice-free areas of West Greenland.
Keywords:Eolian stratigraphy  Holocene  Greenland  Sand sheets  Eolian sedimentology  Arctic environmental change
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号